Experimental and statistical investigation on the performance of asphalt overlays reinforced with geocomposite in controlling the reflective cracks under different loadings and temperatures

Abstract

One of the easiest method to repair the old pavement is to apply an overlay on them. However, the deteriorated pavement affects the overlay performance by propagating the existing cracks upwards to the overlay due to the stress and strain concentration from the loading and temperature variations. Today, using the asphalt overlays reinforced with geosynthetic interlayers is one of the most effective methods to prevent the reflective cracking. This paper investigates the effects of the temperature, bending fatigue loading frequency and geocomposite tensile strength on the asphalt overlays performance experimentally. The crack initiation and its propagation rate were analyzed by the help of image processing technique and statistically. The obtained results revealed that the temperature has the greatest effect on the reflective cracking rate, so that by increasing the temperature from 20 to 40 °C in addition to increasing the crack growth rate and changing the vertical deformation under the load, the direction of crack formation changes, and besides the reflective cracks, the top-down cracks also appear. Furthermore at the higher loading frequency more than 10 Hz, even in samples reinforced with geocomposite, increasing the temperature from 0 to 20 and 40 °C will increase the crack growth rate between 5 and 30 times. The obtained coefficients of determination (R2) and Adjusted R2 are equal to 0.9936 and 0.9907, respectively, indicating the satisfactory prediction of the model compared to the real observations.